Injection systems for internal combustion engines of motor vehicles conventionally include pressure limiting valves. The pressure limiting valves may be integrated into high-pressure fuel pumps, for example, to protect the components from high fuel pressures in the event of thermal expansion or various malfunctions. For example, a pressure limiting valve in a petrol injection system may open at a fuel pressure of 250 bar. The pressure limiting valve may open communication between the high-pressure side and the low-pressure side.
To improve reliable operation of the injection system, very exacting requirements may be set for the accuracy of the opening pressure of the pressure limiting valve. In order to keep the tolerance range small, for example, a hydraulically measuring adjustment method may be used for adjusting the opening pressure. In this example, a spring force acting on the closing element of the pressure limiting valve is varied, conventionally by means of a rotational movement via a thread, for example, until the desired opening pressure is set. The production of two threads necessary for this purpose and the space for a separate seal involves a technical manufacturing outlay and takes up a corresponding amount of overall space.
In the fitted state, moreover, the pressure limiting valves must be sealed against pressures of up to 400 bar without sustaining measurable leakage.